Marathon Makes Discovery on Perseus Prospect

Marathon Oil has made a discovery on the Perseus prospect in Viosca Knoll Block 830 in the deepwater Gulf of Mexico. The Perseus discovery well is located in 3,376 feet of water, approximately 150 miles southeast of New Orleans and approximately five miles from the existing Petronius platform. The well was drilled by Noble Drilling's semisub, Noble Amos Runner.

The discovery well was drilled to a total measured depth of 13,134 feet and encountered 166 net feet of oil pay. Fluid samples indicate the reservoir contains 30 degree API gravity oil. Current plans are to evaluate various development options.

The Perseus discovery is expected to begin production in 2005 and extend the Petronius production profile. Petronius is currently producing at an average of 60,000 barrels of oil and 100 million cubic feet of gas per day.

Marathon holds a 50-percent working interest in both the Perseus discovery and the Petronius development. ChevronTexaco holds the remaining 50-percent interest and serves as operator.